The fallacy of 35mm "equivalent focal lengths"

Started 3 months ago | Discussions thread
Neil-O Regular Member • Posts: 134
Re: Okay. What now?

sybersitizen wrote:

Tony Beach wrote:

When I want an idea of what a camera can do (i.e., what it is equivalent to) I look at its actual focal lengths and apertures, and then the size and pixel density of its sensor. The only limitation actually described by "equivalent focal length" is how wide a FOV you can capture in the file. Many consumers (and even some participants in the forums here at DPR) falsely think that when the camera is sold to them with some extraordinary "equivalent focal length" that they would need an enormous lens to replicate that, and that's misleading and fallacious.

I don't think anyone here would choose to argue with those three sentences ... at least I wouldn't. Maybe this thread would be much shorter if you said exactly that in the first post.

Some (myself included) might feel that there is no guilty party at work intentionally trying to deceive or mislead the population of camera buyers; but rather it's just that many things are more complicated than can be easily presented and digested by the population of buyers of any complex product category, and this qualifies as one of them.

A question now is: Are you in favor of camera manufacturers describing and labeling products differently (replacing equivalent focal length with equivalent FOV) and including the many associated caveats in those descriptions and/or labels? And the same thing regarding camera reviews and forum discussions of equivalence?

I agree.  This is far from the first time someone has raised this issue, but there's a good reason we still use equivalent focal length - no-one has yet come along with an acceptable alternative that doesn't cause further confusion.

I doubt anyone ever will.  There are other walks of life where a rule of thumb exists harking back to days of yore, and I suspect we will still be referencing the 35mm film camera for a very long time after such cameras cease to have any real relevance in the modern world.

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